Red-tailed Cuckoo-bee

The Red-tailed Cuckoo-bee (Bombus rupestris) is a large, impressive cuckoo bumblebee; completely black in colour with a red tail.  Females are covered in black fur which is sparse and often shows the shiny black body underneath, they have very dark, almost black wings, unlike any similar species.  Males have largely undarkened wings, but an indistinct greyish-yellow banding and lack of obvious yellow facial hair separates them from the Red-tailed Bumblebee.

Females emerge in May and go into hibernation before the end of August whilst males continue until mid-September.

• • Size: 16-22mm in length
  • Life span:  Annual life cycle taking approximately one year to complete.  The adult Red-tailed Cuckoo-bee lives for approximately 5-6 months.
  • Diet:  The Red-tailed Cuckoo-bee feeds from a variety of flowers including Kidney Vetch, Oil-seed Rape, Oxeye Daisy, comfrey, dandelion, thistle, ragwort, bramble, teasel and Devils- bit Scabious. this species does not collect pollen to feed offspring.
  • Reproduction:  Female Red-tailed Cuckoo-bees sneak into the nests of worker Red-tailed Bumblebees (Bombus lapidarius) before killing or subduing the queen it then establishes itself as the “queen”, lays its eggs and fools the lapidarius workers into rearing its offspring. Once egg laying is completed, the female Red-tailed Cuckoo-bee dies in the nest.
  • When to see: The Red-tailed Cuckoo-bee is most active from May to late August
  • Population Trend:  Unknown, but thought to be becoming more abundant in Britain in recent years.  However, the Red-tailed Cuckoo-bee is still classed as Scarce in Britain, Endangered in the Regional Red List of Irish Bees and listed as a Northern Ireland Priority Species.
  • Threats:  The survival of Red-tailed Cuckoo-bee is dependent on its host which has been declining due to habitat loss of flower rich grassland where it nests and feeds
  • Fun Fact:  Female Red-tailed Cuckoo-bees take over the nests of Red-tailed Bumblebees and fool the workers into rearing their own offspring.  They also have the largest wingspan of any bee species!

How you can help: 

Buglife is working to increase awareness of invertebrates and the Red-tailed Cuckoo-bee through specific projects, including Belfast’s Buzzing and B-Lines, but we need your help!

Buglife B-Lines are an imaginative and beautiful solution to the problem of the loss of flowers and pollinators. B-Lines are a series of ‘insect pathways’ running through our countryside and towns, along which we are restoring and creating a series of wildflower-rich habitat stepping stones. Linking existing wildlife areas together, creating a network, like a railway, that will weave across the UK landscape.  More information about B-Lines and how you can help pollinators can be found on our B-Lines & Pollinator Projects pages.

Join a recording scheme and log your finds – send any records/sightings to BWARS or download the iRecord app and get recording!

Do remember that we rely on donations to continue our work.  If you have searched, found and learnt about our incredible invertebrates on our website, please do consider Making a Donation, Becoming a Member or maybe even making a purchase in our shop.  For more ideas on how to support our work find out how to Get Involved.  Thank you 🕷

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